Steam box



April 7, 1959 w. G. I'IQOLLINS STEAM BOX Filed Nov;

FIG. 1

INVENTOR. W .G. ROLLINS ATTORNEY- United States Patent STEAM BOX Wilbur G. Rollins, South Zanesville, Ohio Application November 7, 1956, Serial No. 620,864 Claims. or. 34-87) The present invention relates to packaging and more particularly to apparatus and a method for treating a covered package causing the covering to shrink around the article.

Heretofore, various products including meat, have been packaged with a thin transparent film permitting the customers to see the product without any possibility of contamination of such product. Although transparent coverings have been used for a long time, they usually have been loose on the product and when moisture collects on the inner surface have interfered with a clear view of the product. Particularly where the covered product, such as meat, is of irregular shapes, the covering was not drawn tightly around the product and did not uniformly contact the product resulting in poor appearance and reduction in attractiveness, thereby reducing the sales appeal.

The need for satisfactory product packaging and an economical manner of accomplishing the same has not been satisfied with existing equipment or processes, particularly in the large establishments where meat is packaged by a number of butchers and put out for display to the customers. It is essential that the equipment be relatively compact to avoid expensive space requirements and also be readily operated by relatively unskilled labor and will be serviceable for long periods without requiring expensive maintenance.

An object of the present invention is to overcome the above enumerated difficulties of the prior art and to provide suitable apparatus and an efiicient method of treating packages to cause the covering to fit snugly around the contents.

A further object is to provide equipment which is automatically operable in response to the presence of the package to be treated.

A further object is to provide a steam box of general utility which will be inexpensive to manufacture and serviceable for long periods without requiring expensive maintenance or repairs.

Other and further objects will be apparent as the description proceeds and upon reference to the accompanying drawing wherein:

Fig. 1 is a fragmentary isometric view of a portion of a belt conveyor with the steam box of the present invention applied thereto;

Fig. 2, an enlarged longitudinal section with parts broken away and taken substantially on line 2-2, Fig. 1;

Fig. 3, a transverse section through the steam box and the conveyor taken substantially on line 3-3 of Fig. 2; and

Fig. 4, a longitudinal section on a reduced scale of a modified form of a steam box showing anotherform of article contacting switch operating mechanism.

, Briefly, the present invention includes the conveyor of the belt type having a frame structure adjacent its edges and on which frame structure a hood or enclosure having atop and depending sides is mounted, the ends of the enclosure being normally open to permit the pas- Patented Apr. 7, 1959 sage of articles longitudinally through the enclosure. The open ends are provided with suspended curtain-like elements made of rubber or similar flexible material for effectively closing the ends for confining the steam while permitting the curtains to be pushed aside by the articles as they pass into and out of the enclosure or steam box. Steam is supplied to the steam box through a side wall by means of nozzles supplied with steam from a manifold supplied with steam through a low pressure supply pipe in which the steam is controlled by a solenoid operated valve energized by an article contacting trip lever pivotally mounted in the steam box. Steam is sprayed on the covering of a package passing through the en- 'closure heating the covering and shrinking the same so belt 10 is movably supported on rollers 11 rotatively,

mounted in suitable bearings 12, 12 in longitudinal angle frame members 13, 13, respectively, supported at a convenient height by suitable posts or the like, not shown.

An enclosure, having a top 14, sides 15 and 15, is open at the ends except for narrow downwardly extending flanges 16 and 17 at the entrance and exit ends respectively. The sidewalls 15 and 15' are supportingly received in the flanges of the angle iron 13 and 13' being secured thereto by any suitable means, which may include the force of gravity, bolts or the like. By using temporary fastening means the steam box enclosure may be applied to and removed from existing conveyors without changing such conveyors.

To close the ends of the enclosure for returning steam, flexible curtain-like elements 18 and 19 respectively are provided, such curtain-like elements being preferably formed of a flexible sheet material such as rubber or the like which is suspended from the flanges 16 and 17 substantially to the surface of the conveyor 10, the curtains being secured in position at their upper edges by means of straps 20 and suitable bolts 21 passing through the strap 20, the curtain, and the adjacent downwardly extending flange.

Steam is supplied to the steam box by means of a series of nozzles 22, 22 opening into the steam box from one side thereof, 15 for example, as shown in Figs. 1 and 3, and are connected by nipples or other suitable connections to a manifold 23 formed of pipes and T connections, the manifold is supplied with steam through a low pressure line 24 in which the steam flow is controlled by a solenoid operated valve 25, the steam being supplied to the solenoid valve through a low pressure supply line 26 in which the pressure is measured by a gauge 27, the pressure having been reduced by a reduc ing valve 28 supplied with steam from a high pressure line in which the flow is controlled by a manually operated shutoff valve 29.

A normally open micro switch 30 is mounted on the top 14 of the enclosure having a downwardly extending pushbutton 31 which passes through the top of the enclosure. A pair of downwardly extending ears 32, 32 pivotally support a downwardly extending arm 33 integral with a horizontally extending arm 34 connected, the arm 33 having a laterally extending pushbutton operating lug 35 which contacts with the pushbutton 31. A pair of conductor wires 36 extend from the micro switch 30 to a solenoid 37 of the solenoid operated valve 25 and electrical energy is supplied to the solenoid operated valve through a connection box 38 from a source of electric power in a well-known manner. The electrical connection of the micro switch 30 to the solenoid 37 is such as to open the solenoid controlled valve when the trip lever 33, 34 is moved to its dotted line position as shown in Fig. 2 by contacting an article such as a piece of meat 39. The meat having been wrapped in a covering or bag 40 of cellophane is moved by the conveyor 10 from left to right as indicated by the direction arrows, through the curtain 18 and into contact with the knee 33 of the trip lever 33, 34 closing micro switch and thereby opening solenoid-operated valve 25.

When the trip lever is moved to close switch 30 the flow of steam fills the steam box enclosure and as long as an article 39 is in the steam box and in contact with the horizontal portion 34 of the trip lever, the flow of steam flow continues and such steam serves to heat the covering 40 causing the covering to shrink and snugly engage the article 39 so the article with its covering has a neat appearance as it passes through the exit curtain 19, the steam flow being cut olf as soon as the last article passes the rear end of arm 34.

Referring to the modification of the invention shown in Fig. 4, an arm 41 is suspended from a micro switch 42 for swinging movement While a second arm 43 is swingably mounted from a pair of lugs 44 adjacent the exit of the enclosure. A link 45 is pivotally connected at each of its ends to the lower ends of the arms 41 and 43 respectively, whereby an article passing into and through the enclosure serves to cause angular movement of the arm 41 and operate the micro switch 42 whereby the solenoid valve 25 is opened as long as an article is in the enclosure and contacting link 45, the micro switch 42 opening when the last article is discharged under the exit end of link 45. In this modification various size products can be handled without any possibility of interference as long as the article can pass through the entrance or exit.

It will be evident that the present invention is particularly useful for shrinking cellophane coverings which are wrapped around meat for protecting the meat against contamination and to improve the appearance thereof for packaging and for sale. After the cellophane is wrapped around the meat, the meat is passed into the enclosure where contact of the meat package with the trip lever serves to operate the solenoid controlled valve to force steam into the enclosure thereby steaming the cellophane covering resulting in shrinkage of the covering to snugly engage the meat from all sides and the steaming process continues until the last article of a series passes out of the exit end.

It will be evident that the invention is useful on existing conveyors and can be applied as an attachment directly to such existing conveyors. The steam box enclosure can be sold in combination with a conveyor providing a unit which is readily useable in all types of packaging establishments, including retail stores and the like. The steam is removed from the enclosure through the vent 46in its top to avoid steam escaping into the room and objectionably increasing the humidity therein.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is illustrated in the drawing and described in the specification, but only as indicated in the accompanying claims.

I claim:

1. Apparatus for the treatment of small articles comprising a belt conveyor, means to support the belt conveyor for movement in a feeding direction, an enclosure including sides and a top mounted over said belt conveyor and having its ends open, downwardly extending flexible closure members on each end of said enclosure to confine gas within the enclosure, a series of nozzles arranged along one side of the enclosure, a manifold connected to said nozzles, a supply pipe connected to said manifold, a solenoid operated valve in said supply pipe for controlling the flow of steam therethrough, a pivoted lever mounted on said enclosure and adapted to engage articles carried by said conveyor, means to supply electric power to said solenoid, a switch controlled by said lever whereby said lever operates said solenoid to feed steam to said enclosure when an article is located in said enclosure, a pressure gauge and a reducing valve in said supply pipe and a control valve for controlling the flow of steam thereto.

2. Apparatus for the treatment of small articles comprising a belt conveyor, means to support the belt conveyor for movement in a feeding direction, an enclosure including sides and a top mounted over said belt conveyor and having its ends open, downwardly extending flexible closure members on each end of said enclosure to confine gas within the enclosure, a series of nozzles arranged along one side of the enclosure, a manifold connected to said nozzles, a supply pipe connected to said manifold, a solenoid operated valve in said supply pipe for controlling the flow of steam therethrough, a pivoted lever mounted on said enclosure and adapted to engage articles carried by said conveyor, means to supply electrtic power to said solenoid, a switch controlled by said lever whereby said lever operates said solenoid to feed steam to said enclosure when an article is located in said enclosure.

3. Apparatus for the treatment of small articles com prising a conveyor, means to support said conveyor along a path of travel in a feeding direction, an enclosure overlying the path of travel of said conveyor and having open ends, article-displaceable closure members at each end of said enclosure to confine fluid within said enclosure, discharge nozzle means along the path of travel of said conveyor for directing a fluid on articles moving through the enclosure on the conveyor, a pressurized treatment fluid supply source connected to said discharge nozzle means, servo control valve means operatively connected between said supply source and discharge nozzle means for controlling the flow treatment fluid therethrough, an actuating lever in said enclosure adjacent the path of travel of said conveyor for engaging articles carried by said conveyor, power means for operating said seivo control valve means, and control means operatively connected to said power source and controlled by said actuating lever whereby movement of the latter by an article operates said servo control valve means to feed treatment fluid into the enclosure when an article is located therewithin.

4. Apparatus as set forth in claim 3 in which said actuating lever is pivotally supported within said enclosure and includes a portion overlying substantially the entire path of travel of said conveyor within said enclosure, said lever including another portion engageable with said control means for operating the same during the movement of an article along substantially the entire path of travel within said enclosure.

5. Apparatus as set forth in claim 3 including a primary source of high pressure treatment fluid, and pressure regulating means between said primary and supply source of treatment fluid for maintaining a predetermined pressure of treatment fluid in said supply source.

References Cited in the file of this patent UNITED STATES PATENTS 281,201 Oberle et al. July 10, 1883 1,512,918 Forsgard Oct. 28, 1924 2,481,130 Lindemuth Sept. 6, 1949 2,651,313 Toennies Sept. 8, 1953 2,660,513 Ball Nov. 24, 1953 2,668,403 Rumsey Feb. 9, 1954 2,745,419 Slingerland May 15, 1956 2,783,599 Weikert Mar. 5, 1957 OTHER REFERENCES Modern Packaging, March 1948, pages 119, 

